Firefox 63: Everything you need to know

Firefox 63 represents the branch built with the new Quantum engine. It comes with a refined user interface, codenamed "Photon". The browser now comes without support for XUL-based add-ons, so all of the classic add-ons are deprecated and incompatible. See

Thanks to the changes made to the engine and the UI, the browser is amazingly fast. The user interface of the app is more responsive and it also starts up noticeably faster. The engine renders web pages much faster than it ever did in the Gecko era.

Here are the important changes in Firefox 63.

Performance

This version of the browser brings performance improvements to Windows and Mac. This was done by moving the build infrastructure to the Clang toolchain. The Mac version of the browser makes Tab switching notably faster.

Dark and Light theme support in Windows 10

Starting with version 63, Firefox will follow the system theme preference in Windows 10. If you set the dark theme as your system and app theme, Firefox will automatically apply the appropriate built-in theme. You can always change the browser's theme manually from the Customize menu.

Top Sites Shortcuts

There are a number of new search shortcuts in the Top Sites section of Firefox. This change affects users from the United States. The new search shortcuts include Google and Amazon.

You can't disable Firefox updates any more

Starting in version 63, Firefox no longer includes the option to completely disable updates. The option "Never check for updates" is gone from the Preferences\General section. The options you can set now are:

Automatically install updates(recommended)

Check for updates but let you choose to install them

Other interesting changes

The Ctrl + Tab shortcut shows thumbnail previews of tabs for new users.

The tab switching order has changed for the Ctrl + Tab switcher. Now it cycles through tabs in recently used order. This can be disabled in Preferences.

The Tracking Protection feature is now known as Content Blocking. A new shortcut in the main menu opens Preferences on the Privacy & Security page.

There is a separate browser process for WebExtensions on Linux, which improves the performance and stability of the app.

Firefox will reduce animations if the appropriate option is enabled in Ease of Access in Windows.

About Sergey Tkachenko

Sergey Tkachenko is a software developer from Russia who started Winaero back in 2011. On this blog, Sergey is writing about everything connected to Microsoft, Windows and popular software. Follow him on Facebook, Twitter or Google+.